茅台英文RCT神盾局特工第四季百度云：A study design that randomly assigns participants into an experimental group or a control group. As the study is conducted, the only expected difference between the control and experimental groups in a randomized controlled trial (RCT) is the outcome variable being studied.umbilicus
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随机对照试验：将研究对象随机分组，对不同组实施不同的干预，在这种严格的条件下对照效果的不同。在研究对象数量足够的情况下，这种方法可以抵消已知和未知的混杂因素对各组的影响。
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veetaCohort Study：A study design where one or more samples (called cohorts) are followed prospectively and subquent status evaluations with respect to a dia or outcome are conducted to determine which initial participants exposure characteristics(risk factors) are associated with it. As the study is conducted, outcome from participants in each cohort is measured and relationships with specific characteristics determined.
队列研究：是将一个范围明确的人群按是否暴露于某可疑因素及其暴露程度分为不同的亚组，追踪其各自的结局，比较不同亚组之间结局的差异，从而判定暴露因子与结局之间有
无因果关联及关联大小的研究方法。(注明：队列研究可以是回顾性的也可以是前瞻性,院子里也有处指出)
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Ca report study ：A study that compares patients who have a dia or outcome of interest (cas) with patients who do not have the dia or outcome (controls), and looks back retrospectively to compare how frequently the exposure to a risk factor is prent in each group to determine the relationship between the risk factor and the dia.
main病例对照研究：以一组患有某种疾病的人（病例）和一组或几组未患这种疾病的人（对照）作为研究对象，调查他们过去对某个或某些可以病因的暴露情况（有无或暴露剂量），通过对病例组和对照组有关暴露情况的比较，推断研究因素（暴露）作为病因的可能性。（病例对照一定是回顾性的）
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